Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or another food source; a poisonous mushroom is generally called a toadstool. The standard reference for the name is the cultivated white button mushroom, Agaricus bisporus, and the word is most often applied to fungi that have a stem, a cap and gills on the cap's underside, though it also describes a variety of other gilled fungi with or without stems and, more loosely, the fleshy fruiting bodies of some other fungal groups; the gills produce microscopic spores that help the fungus spread. Forms that deviate from this standard shape usually carry more specific names, such as bolete, truffle, puffball or stinkhorn.